VB+SQL数据库图片存取.doc

VB+SQL图片存取vb代码VB窗体界面如下：1.把图片写入到Field中函数代码：Private Sub picsavetodb(ByRef fld As ADODB.Field, diskfile As String) Const blocksize = 4096 Dim bytedata() As Byte Dim numblocks As Long Dim filelength As Long Dim leftover As Long Dim sourcefile As Long Dim i As Long sourcefile = FreeFile Open Trim(CommonDialog1.filename) For Binary Access Read As sourcefile filelength = LOF(sourcefile) If filelength = 0 Then Close sourcefile MsgBox Trim(CommonDialog1.filename) & 无内容或不存在！ Else numblocks = filelength blocksize leftover = filelength Mod blocksize fld.Value = Null ReDim bytedata(blocksize) For i = 1 To numblocks Get sourcefile, , bytedata() fld.AppendChunk bytedata() Next ReDim bytedata(leftover) Get sourcefile, , bytedata() fld.AppendChunk bytedata() Close sourcefile End IfEnd Sub2.把图片存入SQL数据库XS（学生表）中：Private Sub Command1_Click()Dim s As StringDim bytedata() As ByteDim adofld As ADODB.Fields = select * from xs where 学号= & Trim(Text1.Text) & sqlres.Open s, connectstring, adOpenDynamic, adLockPessimisticIf Not sqlres.EOF ThenSet adofld = sqlres.Fields(照片) If CommonDialog1.filename Then Call picsavetodb(adofld, filename) End If sqlres.Update3.把图片从SQL数据库读入VB图片框：Private Sub Command3_Click() Dim sqlres As ADODB.Recordset Set sqlres = New ADODB.Recordset sqlres.Open select * from xs where 学号= & Trim(Text1.Text) & , connectstring, adOpenDynamic, adLockPessimistic Dim stream As ADODB.stream Set stream = New ADODB.stream stream.Mode = adModeReadWrite Image1.Picture = LoadPicture() If Not IsNull(sqlres.Fields(照片) Then stream.Type = adTypeBinary stream.Open stream.Write sqlres.Fields(照片) stream.SaveToFile filename, adSaveCreateOverWrite Image1.Picture = LoadPicture(filename) sqlres.Close stream.Close End IfEnd Sub4修改图片：Private Sub Command2_Click()Dim filename As StringCommonDialog1.Filter = 图像(*.jpg)|*.jpg|位图(*.bmp)|*.bmpCommonDialog1.InitDir = App.Path & 图片库Com